New research seeks to identify location of brain consciousness

Posted Feb 20, 2020 by Tim Sandle
In a quest to identify the location of brain consciousness, scientists have stimulated areas vital to consciousness in monkeys' brains. In doing so, the researchers found this process is sufficient to wake the monkeys up.
A neuropsychologist points to a brain scan showing the brain activity of a paedophile at the Hudding...
A neuropsychologist points to a brain scan showing the brain activity of a paedophile at the Huddinge hospital near Stockholm
Jonathan Nackstrand, AFP
Neuroscience has long pondered where in the brain consciousness, occurs; that is the where internal and external sensations are experienced. The new study indicates that this is within the central lateral thalamus. This inference is drawn from studies involving monkeys, who were placed under anesthesia, and then had their brain areas stimulated. This act to stimulation was sufficient to awake the monkeys and they proceeded to demonstrate normal behaviors.
The thalamus is a large mass of gray matter, situated in the dorsal part of the diencephalon (itself a division of the forebrain). Here thalamic nuclei demonstrate strong reciprocal connections with the cerebral cortex. These form thalamo-cortico-thalamic circuits, and it is these which are believed to be involved with animal consciousness.
With the new study, scientists from University of Wisconsin, Madison, looked at macaques monkeys and undertook investigations using awake, sleeping, and anesthetized animals. Through a series of measurements the researchers succeeded in narrowing down the region of the brain connected to consciousness. This was to a far more specific level compared with previous experiments; this included eliminating some brain areas that previous studies had highlighted as potential areas for consciousness.
The brain simulation aspect consisted of stimulating the central lateral thalamus with a frequency of 50 Hz, via electrodes. With anaesthetized monkeys it was shown that the stimulation was sufficient to wake them up and the animals proceeded to act as if they were awake. However, when the electrical current was deactivated, the monkeys returned to a state of unconsciousness.
An applied aspect of the research is to assist with mental health, to aid those who suffer from disorders of consciousness to live better lives, harnessing the potential of brain stimulation.
The research is published in the journal Neuron, where the research paper is titled "Thalamus Modulates Consciousness via Layer-Specific Control of Cortex."